Measurement Performance And Experimental Study Of A Stiffness Regulating Type Of Overconstrained Parallel Six Dimensional Force Sensor

The over-constrained parallel six-axis force sensor(which is abbreviated as OPSFS in the following).The OPSFS is widely used in the field of heavy load measurement.However,due to force majeure,the stiffness of each branch of the over-constrained structure is usually different,which will affect the measurement performance.The measurement performance is closely related to the stiffness of each branch.In theory,the measurement performance is the best when the stiffness of each branch is completely consistent.However,this ideal state cannot be realized in practice.Based on solving the problem of stiffness difference between branches,this paper puts forward a solution to adaptable stiffness between different branches and offer a simple way to reduce it in difference branches,and develops a new type of stiffness-adjustable over-constrained parallel six-axis force sensor by innovatively designing a variable stiffness branch.The specific research contents are as follows:Taking the stiffness of each branch of the sensor as unknown variable,combined with the measurement principle of OPSFS,a complete measurement model is established.Subsequently,this paper established a method for error analysis and the configuration comprehensive optimization.According to the solution of adjustable branch stiffness proposed in this paper,the basic principle of the four-bar and stiffness-variable structure was selected,and the mathematical model of four-bar and stiffness-variable structure which can be applied to the branch design of the OPSFS is established.As a comparison,the mathematical model of non-adjustable fixed branch is established at the same time.Finally,the two branches are applied to the overall mathematical model of it,and the overall stiffness matrix of the sensor is deduced,which verifies the feasibility of the stiffness adjustment scheme theoretically.According to the overall mathematical model of the sensor,the structural optimization is carried out by using the isotropy and stiffness performance indexes.Finally,the experiment.